contracts: Validate code before deployment (#2330)

* Validate module before storing it in code_cache.

* Bump version.

substrate/node/runtime/wasm/Cargo.lock

@@ -2226,6 +2226,7 @@ dependencies = [
  "srml-system 1.0.0",
  "srml-timestamp 1.0.0",
  "substrate-primitives 1.0.0",
+ "wasmi-validation 0.1.0",
 ]
 
 [[package]]
@@ -3203,6 +3204,15 @@ dependencies = [
  "parity-wasm 0.31.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "wasmi-validation"
+version = "0.1.0"
+dependencies = [
+ "hashbrown 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memory_units 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-wasm 0.31.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "winapi"
 version = "0.2.8"

substrate/node/runtime/wasm/Cargo.toml

@@ -12,7 +12,10 @@ crate-type = ["cdylib"]
 node-runtime = { path = "..", default-features = false }
 
 [features]
-default = []
+default = ["core"]
+core = [
+	"node-runtime/core",
+]
 std = [
 	"node-runtime/std",
 ]